1. Technical Field
The present invention relates to a hermetic rotary compressor having two cylinders and capable of changing performance by simultaneously performing a compressing operation by both the cylinders and interrupting the compressing operation in one of the cylinders and reducing a compressing work. The present invention also relates to a refrigerating cycle device using the hermetic rotary compressor.
2. Background Art
In the general hermetic rotary compressor, an electric motor section and a compressing mechanism section connected to the electric motor section are stored in a hermetic case. The compressing mechanism section compresses a cooling medium gas, and discharges once the cooling medium gas into the hermetic case. Thus, the interior of the hermetic case is of a high pressure. In the compressing mechanism section, a piston is stored in a cylinder room arranged in the cylinder. Further, a vane room is arranged in the cylinder, and a vane is slidably stored in the vane room. A tip edge of the vane is projected onto the cylinder room side, and is pressed and biased by a compression spring so as to elastically contact with the circumferential face of the piston.
Accordingly, the cylinder room is partitioned into two rooms along the rotating direction of the piston by the vane. A sucking section is communicates with one side of one of the rooms, and a discharging section is communicates with the other side of the room. A sucking pipe is connected to the sucking section, and the discharging section is opened to the hermetic case.
In recent years, a hermetic rotary compressor of a two-cylinder type having two sets of cylinders arranged vertically has tended to become standard. In such a compressor, if a cylinder for always (continuously) performing the compressing operation and another cylinder capable of switching between compression and stoppage (non-operation) are arranged, a usable performance range is enlarged so as to be advantageous.
For example, in Japanese Patent Unexamined Publication No. H1-247786, a rotary compressor having two cylinder rooms is disclosed. In this rotary compressor, a high pressure introducing section is provided. The high pressure introducing section compulsorily separates a vane of one of the cylinder rooms from a roller, holds the vane, and sets the cylinder room to a high pressure. The high pressure introducing section thereby interrupts the compressing operation as needed.
In this kind of the compressor, the vane is compulsorily separated from the piston and is held when the other cylinder room is compressed and operated while the operation of one cylinder room is stopped. Therefore, a closing vane room is arranged on the rear face side of the vane. In this compressor, however, vane room does not communicate with the interior of the compressor, and a so-called closing room is formed. Therefore, lubricating oil retained within the hermetic case is not sufficiently supplied to a sliding portion of the vane so that wear, burning, etc. are generated.